Guselkumab APEX Trial Supports New Joint Damage Label

Philip Mease, MD, director of rheumatology research at Providence Swedish Medical Center in Seattle, recently discussed the FDA's recent label expansion for guselkumab (Tremfya; Johnson & Johnson) in psoriatic arthritis. The approval adds inhibition of structural joint damage progression to the drug's label, based on data from the phase 3b APEX trial (NCT04882098).¹ Mease reviewed the trial's patient selection strategy, primary results, and safety profile.

In a previous interview, Mease outlined why the structural joint damage progression outcome matters to patients and how it is measured in clinical trials.

Patient Selection in the APEX Trial

Johnson and Johnson designed APEX to enroll patients considered more likely to progress structurally, according to Mease. The trial included over 900 patients and required at least two erosions on baseline films along with elevated levels of the inflammation marker CRP. Patients were then randomized to guselkumab dosed every 4 weeks, every 8 weeks, or placebo.

"They embarked on a very large trial, over 900 patients, and they were very careful about identifying patients who were more likely than not to have structural damage progression, so for example, they made sure to include patients who had at least two erosions on their baseline films before they received the drug," Mease said.

Primary and Structural End Point Results

The trial's primary end point was an ACR 20 response, capturing improvement in tender and swollen joints along with patient global and pain assessments, Mease said. He noted the ACR 20 result was achieved by a majority of patients and was consistent with prior findings from the DISCOVER 1 and DISCOVER 2 trials. The X-ray data represented the key structural endpoint of the trial.

"The key end point was the x-ray data, and both the every 8-week dose, the approved dose for use in clinical practice, and the every 4-week dose clearly showed statistical improvement compared to placebo, and the two dose arms are very similar to each other in this regard," Mease said.

With the finding now reflected in the label, Mease said clinicians can tell patients guselkumab is proven to inhibit structural damage progression on top of improvements in pain, fatigue, stiffness, and quality of life. He described the medication's overall safety profile as one of the strongest among biologics used in clinical practice.

"It's one of the safest medicines that we use in clinical practice, and I think this is a real win for patients," Mease said.

He noted that the combination of proven structural benefit and an established safety profile makes guselkumab a strong option for patients living with psoriatic arthritis.

Reference

1. FDA approves label expansion, cementing Tremfya as the only IL‑23 inhibitor proven to help stop further joint damage. News release. Johnson & Johnson. May 28, 2026. Accessed July 7, 2026. https://www.jnj.com/media-center/press-releases/fda-approves-label-expansion-cementing-tremfya-as-the-only-il-23-inhibitor-proven-to-help-stop-further-joint-damage